By NICK BUNKLEY

Published: May 20, 2006

The University of Michigan football stadium, already the nation's largest, will gain several hundred seats and 83 private suites as it undergoes the most extensive renovation in its 79-year history, according to preliminary plans approved Friday.

The university's Board of Regents voted to proceed with the project despite the objections of many fans, faculty members and three of the board's eight members. Dissenters contend the changes, including 82-foot-tall towers along the east and west sides, will compromise the game-day atmosphere and blight the bowl-shaped stadium, which was built primarily below ground level.

The $226 million renovation is expected to begin in 2008 and take four years to complete. Home games will not be affected, the university said.

Capacity will increase to 108,251 from 107,501. The new towers, seven feet higher than the video scoreboards in the end zones, will contain private boxes of varying sizes and nearly 3,200 premium indoor and outdoor ''club seats.'' Most existing bench seats will be widened to 18 inches from 16 inches, reducing bleacher capacity by 4,300.

In separate interviews, Bill Martin, the director of athletics, and Laurence B. Deitch, the regents' most vocal opponent of the plan, said they wanted to ensure that Michigan Stadium remained an ''iconic'' architectural landmark. Both acknowledged the need to replace the press box, update restrooms, widen aisles and modernize seating.

Martin said enclosed seating was the best way to pay for such an endeavor. Many colleges have added luxury suites in recent years to augment revenue aside from increasing ticket prices.

''Whatever we do will be respectful to the design and character of Michigan Stadium,'' Martin said.

But Deitch called the project ''killing a gnat with a sledgehammer'' and said the university could simply fix what is wrong with the stadium for $60 million. He said the project as approved would ultimately cost more than university officials had estimated.

Unlike the maligned halo of yellow paint and block letters that was removed soon after its installation around the top of the stadium during a 1998 renovation, this project is irreversible.

''When the public sees what it is, they will be appalled,'' said Deitch, a lawyer in Detroit who has attended Michigan football games for 40 years.

Design for the project is expected to take one year, and the regents must then give their final approval.